Hydraulic elevator.



No. 826,572. PATENTED JULY 24, 1906. J. s. HOYT.

HYDRAULIC ELEVATOR.

APPLICATION FILED HA3. 1. 1904. RENEWED BBQ 7, 1905.

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JOHN S. .HOYT, OF DARIEN, CONNECTICUT.

HYDRAULIC ELEVATOR.

Specification of Letters Patent.

Patented July 24, 1906.

7 Application filed March 1, 1904. Renewed December 7, 1905. Serial No. 290,755-

To all whom, it may concern:

Be it known that I, J oHN' S. HoY'r, a citizen of the United States, residing at Darien, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Hydraulic Elevators, of which the following is a full, clear, and exact specification.

This invention relates to hydraulic elevators, and has particular reference to the means for automatically stopping the car at the ends of its travel.

The objectcf the invention is to provide mechanism foroperating the limitation sto valve at both ends of the well, which mechanism will be certain and positive in its operation and at the same time shall operate in connection with high-speed elevators without shock to the apparatus. Heretofore it has been customary to o crate these valves by cables; but the use of cables in this connection is objectionable, because the lightweight cables used to operate these valves are subject to constant variation in len th, due to changes in temperature and stretch of the cable. This tends to make the action of the valve uncertain and unreliable. If the cables stretch, the valve may not be operated soon enough. If they shrink, the valve ma be operated too soon, and thus the car wiil not always be stopped at the r0 er place. Again, the variation in the lengt 1 o the cable may cause the stop-valve to be partially closed when the car is running under normal conditions and thereby interfere with its speed and control. Another disadvantage in-the use of cables is that when used in connection with high-speed elevators their action cannot always easily be graduated to take place through a considerable distance, as is necessary in such elevators. In such devices as the car slows up the movement of the Valve correspondingly slows u whereas the movement of the valve shoul be in inverse ratio to the speed of the car in order to secure the quickest stop without shock or dan er. I therefore ropose to provide mec anism which sha not be dependent upon a cable subject to variation in length ano which mechanism shall be dependent for its operation only upon the position of the car or, if preferred, the counterweight.

The invention will be more fully described in connection with the accompanying drawings, in which- Figure 1 represents a hydraulic elevator system, partly in section, having my improvements applied thereto; and Fig. 2, a detail view.

Referring to the drawings, 1 represents the main cylinder, having therein the plunger 2, carrying the car 3. Attached to the frame of the car 3 is a cable 4, carrying a counterweight 5 and running over sheaves 6. The counterweight runs in guides 14. The main cylinder is supplied with fluid under pressure through the to-and-from pipe 7, which connects the cylinder with the source of supply.

10 is the main valve, having the inlet-port 8 and the outlet-port 9 and communicating,

res ectively, through the passages 11 and 12, wit the automatic valve 13. The main valve may be operated in any suitable manner by the operator on the car through the pilot-valve 15. As shown, the automatic valve consists of two independent valves 18 19, one for stopping at the top and controlling the assage 11 and the other for stopping at the bottom and controlling the passage 12. Each of these valves 18 19 is preferably of the balanced-piston type and is o erated by a rod 20 21, respectively, T e valve 19 is operated by a lever 22, pivoted at 23 and having a lateral extension 24:, which lies in the path of an upright cam 25, carried by the frame of the car. As the car descends the lower portion of the cam strikes the projection 24. of the lever 22, and continued downward movement of the car moves the lever sufficiently to close the passa e 12 and stop the exhaust, as shown in the (Trawings.

26 is a weight for retracting the valve in the assa e 12. v T e va vs 18 for cutting off the supply to stop the car at the top is operated by a lever 28, similar to the lever 22. The car may be stopped at the top by causing the counterweight to close the valve. This is accomplished by providing the counterweight 5 with a cam 31, similar to the cam 25 on the car, which will operate the lever 28 and the valve 18 as it approaches its lowest position. 32 is a weight which returns the valve to open position after the cam 31 has operated the lever 28. It will be seen that the car can car and the distance in be started in the opposite direction in the ordinary manner by the operator, as but one passage to the cylinder is closed at a time, the other for going in the opposite direction remaining open. The cables connectin the counterweight with the car are ordinari y of sufiicient number and sufficiently large to prevent variations in length, and hence the operation of the valve by the counterweight is not objectionable. On account of the construction of the levers 28 and 22 and their respective cams 31 and 25 the valves will n'ecessarily be closed gradually without shock and will always bring the car to a stop at exactly the same place. The configuration and throw of the cams and the levers will be to the speed of the which it is desired to stop the car. It will thus be seen that the invention can be applied to any car and that by merely changing the design of the cams and levers it will be capable of use with cars of varying speeds. Another feature of advantage is that all of the operative parts are in proximity to the valve mechanism, and there is no mechanismin the elevator-well.

I do not restrict myselfto the use of separate valves for stopping the car, as a single valve (located, for example, in the pipe 7) may obviously be arranged to be closed by contact of car and counterweight with the levers 22 and 28 without departing from the invention. In the arrangement shown in the drawings in case the counterweight should break loose from the car it would fall and immediately close the valve 18, and thus prevent further upward movement of the car and possible accident at the top of the shaft. If but one valve be employed, a separation of car from counterweight would cause the counterweight to close the valve, and thus prevent further movement of the car in either direction.

It will be understood, of course, that although I have shown the levers 22 28 connected dlrectly to the valve-stems any suitproportioned according able intermediate connection between the part moved by the car and the valve may be employed.

Modifications and change may be made without departing from the scope of the invention, and I do not desire to be limited to the exact construction I have shown.

What I claim as new, and desire to secure by Letters Patent, is as follows:

1. The combination with the car, and a counterweight, of valve mechanism for stopping the movement of the car, said mechanism being actuated alternately and directly by contact with meanson the car when the latter is at the lower end of its travel, and by means on the counterweight when the latter 1 is at the lower end of its travel.

2. The combination ofa car, a counterweight connected therewith, guides for the counterweight, an automatic valve having operating connections projecting into the path of the counterweight, and cam mechanism on the counterweight adapted to actuate said valve connections, substantially as described.

3. The combination with the car, of a counterweight connected therewith and sliding in guides, an automatic limit-stopping mechanism having a lever projecting into the path of the counterweight, and cam mechanism on said counterweight for actuating said lever, substantially as described.

4-. The combination with the car, of a main valve, inlet and exhaust ports leading from said main valve to an automatic valve, said automatic valve com rising an independent valve for each port, a ever for operating e'a-ch valve, means on the car for directly actuating one of said levers, and means on the counterweight for directly actuating the other of said levers, substantially as described.

5. The combination with a car having a counterweight, of automatic mechanism located at the bottom of the well for stopping the car at the top of the well, the counterweight having means adapted to actuate said mechanism at the lower end of its travel, substantially as described.

6. The combination with the main cylinder and the car, of valve mechanism forclosing the passage of fluid to or from the cylinder, and means independent of the "car and confined to'the immediate proximity of, the valve mechanism for operating the latter, said means being operated by direct contact with means on the car and counterweightr'espectively when the latter are at the lower ends of their travel, substantially as described.

7 The combination with a car having a counterweight, of an automatic valve at the lower end of the elevator-shaft, and acam on the counterweight adapted to actuate the automatic valve for stopping the car at the top when the counterweight is at the bottom, substantially as described.

8. The combination with a car having :a counterweight, of an automatic stopping mechanism, and means whereby the separation of the car from the counterweight 'actu. ates said mechanism, substantially as de scribed.

9. The combination with a car having a counterweight, of automatic mechanism for stopping the car at the ends'of the well,said mechanism being actuated directly by the respective downward 'movements of the car and counterweight, whereby said mechanism maybe confined to the immediate proximity of the lower endof the shaft, substantially as described.

10. The combination with a hydraulic elerespective movements, substantially as de- IO vator having a counterweight, of valve mechscribed. anism for closing the supply or exhaust In testimony whereof I affix my signature when the car is at the respective ends of its in presence of two witnesses. travel, said valve mechanism being located at the lower end of the well, and means whereby JOHN HOYT said valve mechanism is actuated by direct Witnesses: contact respectively with means on the car JOSEPH CARSON,

and counterweight at the lower ends of their C. V. EDWARDS. 

